Investigations of the enzymatic and chemical properties of elongation factor 2, the protein that catalyzes the translocation step in polypeptide chain elongation in eukaryotic cells, are continuing. The amino acid sequence at the site of the factor's inactivation by NAD ion and diphtheria toxin has been delineated. The ADP ribose moiety of NAD ion is covalently bound to a slightly basic alpha amino acid which has not heretofore been described. Attempts to obtain sufficient quantities of the unknown residue to identify by mass spectrometry and nuclear magnetic resonance are in progress. A project is underway to study the cell-free synthesis of the placental polypeptide hormones, HPL and HCG. A fraction of poly(A)- containing RNA has been isolated from term placenta which serves as a messenger RNA in a cell-free system from wheat germ. A product closely resembling HPL, but with a slightly higher molecular weight, has been identified. The possibility that the product is a natural precursor of HPL is under investigation.